﻿#region License

// Copyright 2007-2008 Rory Plaire (codekaizen@gmail.com)
/*
 * This license governs use of the accompanying software. If you use the software, you
 * accept this license. If you do not accept the license, do not use the software.
 *
 * 1. Definitions
 * The terms "reproduce," "reproduction," "derivative works," and "distribution" have the
 * same meaning here as under U.S. copyright law.
 * A "contribution" is the original software, or any additions or changes to the software.
 * A "contributor" is any person that distributes its contribution under this license.
 * "Licensed patents" are a contributor's patent claims that read directly on its contribution.
 *
 * 2. Grant of Rights
 * (A) Copyright Grant- Subject to the terms of this license, including the license conditions
 *     and limitations in section 3, each contributor grants you a non-exclusive, worldwide,
 *     royalty-free copyright license to reproduce its contribution, prepare derivative works
 *     of its contribution, and distribute its contribution or any derivative works that you create.
 * (B) Patent Grant- Subject to the terms of this license, including the license conditions and
 *     limitations in section 3, each contributor grants you a non-exclusive, worldwide, royalty-free
 *     license under its licensed patents to make, have made, use, sell, offer for sale, import,
 *     and/or otherwise dispose of its contribution in the software or derivative works of the
 *     contribution in the software.
 *
 * 3. Conditions and Limitations
 * (A) No Trademark License- This license does not grant you rights to use any contributors'
 *     name, logo, or trademarks.
 * (B) If you bring a patent claim against any contributor over patents that you claim are
 *     infringed by the software, your patent license from such contributor to the software
 *     ends automatically.
 * (C) If you distribute any portion of the software, you must retain all copyright, patent,
 *     trademark, and attribution notices that are present in the software.
 * (D) If you distribute any portion of the software in source code form, you may do so only under
 *     this license by including a complete copy of this license with your distribution. If you
 *     distribute any portion of the software in compiled or object code form, you may only do so
 *     under a license that complies with this license.
 * (E) The software is licensed "as-is." You bear the risk of using it. The contributors give no
 *     express warranties, guarantees or conditions. You may have additional consumer rights under
 *     your local laws which this license cannot change. To the extent permitted under your local laws,
 *     the contributors exclude the implied warranties of merchantability, fitness for a particular
 *     purpose and non-infringement.
 *
 */

#endregion License

namespace NPack.Interfaces
{
    /// <summary>
    /// Every class that defines a + operation
    /// like <c>T operator + (T a, T b)</c> should consider
    /// implementing this interface.
    /// </summary>
    /// <typeparam name="T">Type which is addable.</typeparam>
    /// <remarks>
    /// Adapted from an article on lambda-computing.com:
    /// http://www.lambda-computing.com/publications/articles/generics/IArithmetic.cs.
    /// </remarks>
    public interface IAddable<T>
    {
        /// <summary>
        /// Returns the sum of the Object and <paramref name="b"/>.
        /// It must not modify the value of the Object.
        /// </summary>
        /// <param name="b">The second operand.</param>
        /// <returns>The sum.</returns>
#if DOTNET40

        [System.Diagnostics.Contracts.Pure]
#endif
        T Add(T b);
    }
}